It has previously been proposed to cut two narrow slots, parallel to the axis of a plate cylinder, into its circumference. The slots extend at an angle with respect to the tangent of the outer circumference of the plate cylinder, at the point of intersection of the slot with the surface. The slots are arranged to receive respective ends of the printing plate.
German Utility Model Publication DE-GM No. 16 11 416 describes an arrangement to secure a metal foil on the cylinder of a duplicating machine. The structure is characterized by its simplicity--which, however, is not the case with respect to its manufacture. Forming two parallel slits, of very small width dimension, is difficult. The slits must be narrow so that the ends of the metal foil can be reliably secured. Manufacture of such slits must be done with material removing tools, in which the cut must be made at an inclination to the surface of the cylinder. The cut must be made accurately, since the slits must be precisely parallel to the axis of the cylinder.
While it is possible to make slits of this type in cylinders of the limited length used in copy machines, or duplicating machines, it is practically impossible to make slits of this type in the much larger and substantially longer cylinders used in printing machines which, for example, are employed in newspaper printing and the like. The cost of making such slits, of the small width required, which extend precisely parallel to the axis of the cylinder, is excessive.